Replace string with contents of a file using sed

Question

I have two different files:

File1

/home/user1/  
/home/user2/bin  
/home/user1/a/b/c

File2

<TEXT1>
<TEXT2>

I want to replace the <TEXT1> of File2 with the contents of File1 using sed. I tried this command, but not getting proper output:

cat File2|sed "s/<TEXT1>/$(cat File1|sed 's/\//\\\//g'|sed 's/$/\\n/g'|tr -d "\n")/g"

You can use other tools also to solve this problem.

Please paste that error message so we can locate its source. Also tell us which sed implementation are you using. You code works for me with GNU sed. — manatwork, Sep 08 '11 at 14:40
Sorry, Not getting an error. I am not getting desired output. Output is like /home/user1/ n/home/user2/bin n/home/user1/a/b/cn <TEXT2>. Not getting new lines. — chanchal1987, Sep 08 '11 at 14:51
Not sure if this would apply in your specific case, but with diff and patch tools allow to replace some lines in a file by other lines quite easily. — Stéphane Gimenez, Sep 08 '11 at 14:54
Btw, using random data gathered with $() in a sed script makes my eyes bleed. Never use external data in places where some characters are interpreted with special meaning. — Stéphane Gimenez, Sep 08 '11 at 14:59
Similar question: Substitute pattern within a file with the content of other file — Toby Speight, Aug 02 '16 at 09:36
Possible duplicate of How to replace text between two markers in a file with a section of text from another file? — Kusalananda, Jun 07 '17 at 09:58

score 25 · Accepted Answer · answered Sep 08 '11 at 14:48

25

Here's a sed script solution (easier on the eyes than trying to get it into one line on the command line):

/<TEXT1>/ {
  r File1
  d
}

Running it:

$ sed -f script.sed File2
/home/user1/
/home/user2/bin
/home/user1/a/b/c
<TEXT2>

answered Sep 08 '11 at 14:48

Kusalananda

333,661

Thanks this is working. But I don't want to use any other script file. Are there any inline solution? – chanchal1987 Sep 08 '11 at 14:57
Sure: sed '/<TEXT1>/{rFile1^Md^M}' File2, where "^M" is you pressing return. The problem is that sed really needs the newlines within the {...} to delimit the r and the d command. – Kusalananda Sep 08 '11 at 15:46
6

with bash, posix-style strings are a bit cleaner: sed $'/<TEXT1>/ {r File1\n d}' – glenn jackman Sep 08 '11 at 17:18
9

Also with -e for a one liner: sed -e '/<TEXT1>/{r File1' -e 'd}' File2 – sdaau Jun 07 '12 at 14:12
1

And what if instead of replacing the entire line containing <TEXT1>, I just want to replace the string itself, leaving the rest of the line intact? Text1: <TEXT1> to Text1: <file_contents>. – Robin Winslow May 10 '14 at 17:13
@RobinWinslow - you could use any of the working solutions here (you will just have to slightly adjust the code to replace the pattern instead of appending after pattern). – don_crissti Apr 15 '15 at 15:51

marcas756 · Answer 2 · 2014-10-26T09:35:41.020

14

Took me a long time to find this solution using var replacement. All sed solutions did not work for me, as they either delete complete lines or replace incorrectly.

FILE2=$(<file2)
FILE1=$(<file1)
echo "${FILE2//TEXT1/$FILE1}"

Replaces all occurences of TEXT1 in file2 against content of file1. All other text remains untouched.

edited Oct 26 '14 at 09:35

answered Oct 26 '14 at 09:27

marcas756

141

very nice. possibly faster than sed too, since those "expansions" (aka replacements) are built into the shell (bash at least) – mellow-yellow Nov 25 '19 at 21:17
Thank you! You can pip multiple files to this genius method using a while read method described here – Mossab Jan 05 '23 at 16:51

score 7 · Answer 3 · answered Sep 08 '11 at 15:11

I answer because the diff/patch method might be of interest in some cases. To define a substitution of lines contained in file blob1 by lines contained in blob2 use:

diff -u blob1 blob2 > patch-file

For example, if blob1 contains:

hello
you

and blob2 contains:

be
welcome
here

the generated patch-file will be:

--- blob1   2011-09-08 16:42:24.000000000 +0200
+++ blob2   2011-09-08 16:50:48.000000000 +0200
@@ -1,2 +1,3 @@
-hello
-you
+be
+welcome
+here

Now, you can apply this patch to any other file:

patch somefile patch-file

It will replace hello,you lines by be,welcome,here lines in somefile.

this is really clever but would be better if you could automate it in a script — qodeninja, Jun 24 '18 at 02:20

Replace string with contents of a file using sed

File1

File2

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